JPH069828A - Polyolefin resin composition - Google Patents

Abstract

PURPOSE:To improve weld elongation of molded article having a weld part. CONSTITUTION:A polyolefin resin composition comprises (a) 20-60wt.% polyolefinic resin having <=200,000 molecular weight of main peak measured by GPC (gel permeation chromatography) and <=3.5 molecular weight distribution (ratio of weight-average molecular weight to number-average molecular weight), (b) 30-60wt.% polyphenylene ether and (c) 5-35wt.% at least one copolymer selected from a vinyl aromatic compound-conjugated diene compound copolymer and a hydrogenated substance of vinyl aromatic compound-conjugated diene compound copolymer. Since the polyolefinic resin composition having controlled specific molecular weight and molecular weight distribution is used, weld elongation of a molded article having a weld part of a composition comprising a polyolefin, a polyphenylene ether and a compatibilizer is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin resin composition having excellent oil resistance, chemical resistance, heat resistance and impact resistance, which can be used in electric / electronic fields, automobile fields, and various other industrial material fields. is there.

[0002]

2. Description of the Related Art Polyphenylene ether has excellent transparency, mechanical properties, electrical properties, heat resistance, low water absorption and excellent dimensional stability, but has the disadvantage of poor moldability and impact resistance. By blending with polystyrene and high-impact polystyrene, the problems of molding processability and impact resistance are improved, and it is widely used for industrial parts, electric / electronic parts, office equipment housings, automobile parts, precision parts, etc. However, a classical polyphenylene ether resin composition composed of this polyphenylene ether and high-impact polystyrene (US Pat.
(Disclosed in US Pat. No. 383435) has improved impact resistance, but has a drawback of poor chemical resistance.

For this reason, for example, US Pat.
No. 51, Japanese Patent Publication No. 42-7069 proposes to improve solvent resistance and impact resistance by blending polyphenylene ether with polyolefin.
US Pat. No. 3,994,856 describes improvement in impact resistance and solvent resistance by blending polyphenylene ether or polyphenylene ether and styrene resin with a hydrogenated block copolymer, and US Pat. No. 4,145,377. In the specification, a polyphenylene ether or a polyphenylene ether and a styrene resin are used as a polyolefin / hydrogenated block copolymer = 20.
~ 80 parts by weight / 80 to 20 parts by weight of a premixture and a hydrogenated block copolymer are blended to improve impact resistance and solvent resistance, and further, there is a description in US Pat. No. 4,166,055 and US Pat. Patent No. 42
39673 describes improving impact resistance by blending polyphenylene ether with hydrogenated block copolymers and polyolefins. U.S. Pat. No. 4,383,082 and EP-A-115712 describe that polyphenylene ether is blended with a polyolefin and a hydrogenated block copolymer to improve impact resistance.

Further, JP-A-63-83149, JP-A-63-113058, and JP-A-63-1280.
64, JP-A-63-218748, JP-A-63-225642, and JP-A-63-245453.
JP-A No. 64-40556, JP-A No. 1-9
No. 8647, No. 1-204939, No. 1-2221444, No. 2-4844, No. 2-4845, No. 2-92957.
Japanese Patent Laid-Open No. 2-103243, Japanese Patent Laid-Open No. 2-1
No. 10147, No. 2-158641, No. 2-169635, No. 2-225563.
JP-A-2-248446 and JP-A-2-248447 disclose a specific hydrogenated block copolymer or block copolymer for modifying a resin composition comprising a polyolefin resin and a polyphenylene ether resin. Has been proposed, and a resin composition excellent in chemical resistance and processability has been proposed.

[0005]

The above-mentioned inventive step is certainly compatible with the mixing of the polyphenylene ether and the polyolefin resin (presence or absence of delamination of the composition when the two components are mixed). However, it has been revealed that it does not necessarily have sufficient compatibility when used in complicated molding processes accompanied by the recent progress of molding technology. That is, the resin composition obtained by the above-mentioned prior art, when subjected to molding processing conditions having a welded portion as a molded body, extreme orientation of the welded portion occurs, the mechanical strength is notably reduced in elongation, Under the present circumstances, the resistance to external pressure and internal pressure in the case of forming various molded bodies is lowered, and the fracture at the weld portion is facilitated.

The object of the present invention is to improve the weld characteristics of a resin composition containing a polyolefin resin and polyphenylene ether, which cannot be achieved by the above-mentioned prior art,
It is to provide a polyolefin resin composition having excellent oil resistance and heat resistance.

[0007]

In view of the above situation, the present inventors have made a resin composition comprising a polyolefin resin known in the prior art, polyphenylene ether, and a block copolymer acting as an admixture of both. As a result of extensive studies on the weld characteristics of the object, it is possible to significantly improve the weld characteristics, especially the weld elongation, which was difficult in the conventional technique, by using a polyolefin resin having a specific controlled molecular weight and molecular weight distribution. Further, they have found that the present invention can provide a polyolefin resin composition having excellent oil resistance and heat resistance, and reached the present invention.

That is, according to the present invention, (a) the molecular weight of the main peak measured by GPC (gel permeation chromatography) is 200,000 or less, and the molecular weight distribution (ratio of weight average molecular weight to number average molecular weight) is 3.5. The following polyolefin resin 20
-60% by weight (b) Polyphenylene ether 30-60% by weight (c) At least one selected from hydrogenated aromatic vinyl compound-conjugated diene compound copolymer and hydrogenated vinyl aromatic compound-conjugated diene compound copolymer Copolymer of
A polyolefin resin composition comprising 5 to 35% by weight is provided.

As the polyolefin resin used in the present invention, for example, isotactic polypropylene,
Ultra high molecular weight isotactic polypropylene, poly (4
-Methyl-1-pentene), polybutene-1, high-density polyethylene, ultra-high-molecular-weight high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ultra-low-density polyethylene with a density of less than 0.90, ethylene, propylene,
Copolymers of two or more compounds selected from other α-olefins, unsaturated carboxylic acids or their derivatives, for example ethylene / butene-1 copolymers, ethylene- (meth)
Acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, propylene / ethylene (random, block) copolymer, propylene / 1-hexene copolymer, propylene / 4-methyl-1-pentene copolymer Examples include coalescing. These polyolefins may be used alone or in combination of two or more. Of these, polypropylene-based polyolefin is preferable.
These polyolefin resins are polyolefins having a main peak molecular weight of 200,000 or less measured by GPC (gel permeation chromatography) and a molecular weight distribution (ratio of weight average molecular weight to number average molecular weight) of 3.5 or less. It must be a system resin. The polyolefin resins used as polyolefin resin compositions so far are out of this range. Also,
Usually, there are known commercially available isotactic polypropylenes having a main peak molecular weight of 200,000 or less, but the molecular weight distribution is 4 to 9 and cannot be used in the present invention. The polyolefin resin having such a specific controlled molecular weight structure may be prepared by changing the polymerization conditions or chemically cutting a commercially available polyolefin resin with an organic peroxide or the like, or by thermally cutting the molecule at a high temperature. The chain may be cleaved, and the production method is not limited as long as it has the above-mentioned molecular weight structure. Examples of organic peroxides that can be used for controlling the molecular weight include dicumyl peroxide and di-tert.
-Butyl peroxide, tert-butyl cumyl peroxide, 2,5-dimethyl-2,5-di (tert)
-Butylperoxy) hexane, 2,5-dimethyl-
2,5-di (tert-butylperoxy) hexyne-
3, n-butyl-4,4-bis (tert-butylperoxy) valerate, 1,1-bis (tert-butylperoxy) 3,3,5-trimethylcyclohexane and the like are mentioned, and preferred among these. You can choose more than one.

In order to obtain the information on the molecular weight of the above-mentioned polyolefin resin, for example, it is measured by using GPC (gel permeation chromatography) at a temperature of about 140 ° C. with 1,2,4-trichlorobenzene as a solvent. You can Further, the polyolefin resin used in the present invention is, in addition to the above-mentioned polyolefin, 30 to 30% of the polyolefin and α, β-unsaturated carboxylic acid or a derivative thereof in a molten state or a solution state in the presence of an organic peroxide. Three
Polyolefin system modified at a temperature of 50 ° C. and having the above-mentioned specific controlled molecular weight and molecular weight distribution (0.01 to 10% by weight of the α, β-unsaturated carboxylic acid or its derivative grafted or added) It may be a resin, or may be a mixture of the above-mentioned polyolefin resin having a specific molecular weight control and the modified polyolefin resin having a specific molecular weight control in an arbitrary ratio.

The molecular weight of the main peak of such a polyolefin resin (including modified products) measured by GPC is 200.
If the molecular weight distribution is 000 or less and the molecular weight distribution does not satisfy 3.5 or less, the weld elongation of a molded product having a welded part molded from the obtained polyolefin resin composition is significantly reduced, which is not preferable. Next, the polyphenylene ether used in the present invention (hereinafter simply referred to as PPE) is
The PPE is an essential component for imparting heat resistance to the polyolefin resin composition of the present invention.

[0012]

[Chemical 1]

(Where R1, R2, R3, and R4
Are hydrogen, halogen, a primary or secondary lower alkyl group having 1 to 7 carbon atoms, a phenyl group, a haloalkyl group, an aminoalkyl group, a hydrocarbonoxy group, or at least two carbon atoms each being a halogen atom. Selected from the group consisting of halohydrocarbonoxy groups separating an oxygen atom, which may be the same or different.
A homopolymer having a reduced viscosity (0.5 g / dl, chloroform solution, measured at 30 ° C.) of 0.15 to 0.70, more preferably 0.20 to 0.60. Alternatively, it is a copolymer.

Specific examples of this PPE include, for example, poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), poly ( 2-methyl-6-phenyl-
1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether), and the like, and further 2,6-dimethylphenol and other phenols (for example, 2,3,6-trimethyl). Also included are polyphenylene ether copolymers such as copolymers with phenol and 2-methyl-6-butylphenol). Among them, poly (2,6-dimethyl-1,4-phenylene ether),
A copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol is preferable, and poly (2,6-diphenylphenol)
6-dimethyl-1,4-phenylene ether) is preferred.

The PPE is not particularly limited as long as it is obtained by a known method, and for example, a complex of cuprous salt and amine by Hay described in US Pat. No. 3,306,874 is used as a catalyst. Two
It can be easily produced by oxidative polymerization of 6-xylenol. Besides, it can be easily produced by the method described in U.S. Pat. Nos. 3,306,875, 3,257,357 and 3,257,358, Japanese Patent Publication No. 52-17880, Japanese Patent Laid-Open Nos. 50-51197 and 63-152628. .

The PPE used in the present invention is, in addition to the above PPE, the PPE and the α, β-unsaturated carboxylic acid or its derivative in a molten state in the presence or absence of a radical generator, 8 in solution or slurry
Known modified (0.01 to 10% by weight of the α, β-unsaturated carboxylic acid or its derivative is grafted or added) PP obtained by reacting at a temperature of 0 to 350 ° C
E may be used, and the above PPE and the modified PP may be used.
It may be a mixture of E in any proportion.

And further, 9,10-dihydro-9-
Oxa-10-phosphaphenanthrene was added to PPE10.
The phosphorus compound-treated PPE obtained by adding 0.2 to 5 parts by weight to 0 parts by weight and melt-kneading the PPE has excellent color tone and fluidity.
It can be used as PE. In addition, the above PPE
In addition to these, PPE to which polystyrene is added within a range not exceeding 50% by weight can also be suitably used.

Vinyl aromatic compound used in the present invention
The hydrogenated product of the conjugated diene compound copolymer or the vinyl aromatic compound-conjugated diene compound copolymer acts as an admixture of the above-mentioned polyolefin resin and polyphenylene ether (hereinafter, abbreviated as "compatibilizer"). These copolymers are copolymers obtained by copolymerizing vinyl aromatic compounds and conjugated diene compounds, and hydrogenated products (copolymers of copolymers obtained by copolymerizing vinyl aromatic compounds and conjugated diene compounds). At least 90%, preferably 95% or more of the olefinic double bonds based on the conjugated diene compound are hydrogenated), and at least one of these copolymers is used in the present invention.

Examples of the copolymerization form of this compatibilizer include random copolymers, block copolymers, graft copolymers and combinations thereof, among which block copolymers are preferred. Examples of vinyl aromatic compounds that compose this compatibilizer include:
Styrene, α-methylstyrene, vinyltoluene, p-
One or more selected from tert-butylstyrene, diphenylethylene and the like, and styrene is preferred among them. The conjugated diene compound is, for example, one or two of butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like.
One or more kinds are selected, and among them, butadiene, isoprene and a combination thereof are preferable.

Examples of such a compatibilizer include a styrene-butadiene copolymer obtained by anionic polymerization and a hydrogenated product of this styrene-butadiene copolymer. It can be easily produced by the method described in No. 1130770, US Pat. Nos. 3,281,383 and 3639517, or the method described in British Patent No. 1020720, US Pat. Nos. 3,333,024 and 4,501,857.

These compatibilizers are usually 1
It is a copolymer obtained by copolymerizing 5 to 95% of the above vinyl aromatic compound. The amount of the vinyl aromatic chemical is determined in consideration of the miscibility of the polyolefin and the polyphenylene ether, and one or more copolymers containing the vinyl aromatic chemical in the amount are arbitrarily selected as the compatibilizer. To be done.

The number average molecular weight of this compatibilizer is 5,000 to 1,000,000, preferably 10,000 to 800,000, more preferably 3
The molecular weight distribution [ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / Mn)] is 10 or less. Furthermore, the molecular structure of this compatibilizer may be linear, branched, radial, or any combination thereof. As this compatibilizer, for example, "Toughprene", "Sorprene" from Asahi Kasei Kogyo Co., Ltd.,
Commercially available products under the trade names of "Tufden", "Asaprene" and "Tuftec" can be used.

The polyolefin resin composition of the present invention comprises the above-mentioned respective components, and the amount ratio of such components is determined in consideration of the balance of heat resistance, impact resistance, oil resistance and the like of the resulting composition. It That is, the polyolefin resin used in the present invention is usually 20 to 60% by weight, preferably 2
It is 0 to 40% by weight. The polyphenylene ether content is usually 30 to 60% by weight, preferably 40 to 60% by weight, and is selected from hydrogenated vinyl aromatic compound-conjugated diene compound copolymer and vinyl aromatic compound-conjugated diene compound copolymer. The amount of at least one copolymer is usually 5 to 35% by weight, preferably 10 to 30% by weight.

In the present invention, in addition to the above components, other optional components such as a flame retardant (aromatic halogen-based flame retardant,
Aromatic phosphate ester flame retardants, red phosphorus flame retardants), flame retardants, antioxidants, weather resistance improvers, polyolefin nucleating agents, slip agents, inorganic or organic fillers and reinforcing materials (glass) Fibers, carbon fibers, whiskers, mica, talc, calcium carbonate, potassium titanate, wollastonite, etc.), various colorants, plasticizers, release agents and the like may be added.

The polyolefin resin composition of the present invention can be manufactured by various methods. For example, a heat-melting and kneading method using a single-screw extruder, a twin-screw extruder, a roll, a kneader, a Brabender plastograph, a Banbury mixer and the like can be mentioned. Among them, the melt-kneading method using a twin-screw extruder is most preferable. The melt-kneading temperature at this time is not particularly limited, but can be usually selected arbitrarily from 150 to 350 ° C. The polyolefin resin composition obtained in the present invention can be obtained as a resin molded product of various parts by, for example, compression molding, injection molding, extrusion molding, blow molding and the like.

These various parts can be used in the fields of automobiles and electric / electronic fields where there is a high social need for product safety. For example, as automobile parts, bumpers, doors, door panels, fenders, moldings, emblems, wheel covers, engine hoods, etc. , Exterior parts such as roof, spoiler, instrument panel, console box,
Interior parts such as trim, OA equipment as electrical parts,
TV, VCR, video camera, video game,
It is suitable for cabinets or cases of internal and external parts such as various disc players.

[0027]

EXAMPLES The present invention will be described in more detail by way of examples, which should not be construed as limiting.

[0028]

[Reference Example 1] Isotactic polypropylene (main peak molecular weight 278,000, molecular weight distribution 8.5)

[0029]

[Reference Example 2] Isotactic polypropylene (main peak molecular weight 278,000, molecular weight distribution 8.5) 100
2,5-dimethyl-2,5-di (te
rt-Butylperoxy) hexane 0.1 part by weight was added, and the twin-screw extruder (ZSK-25; W was set to 250 ° C.).
ERNER & PFLEIDERER, Germany) was melt-kneaded to obtain polypropylene having a main peak molecular weight of 150,000 and a molecular weight distribution of 3.2.

[0030]

[Reference Example 3] Isotactic polypropylene (main peak molecular weight 278,000, molecular weight distribution 8.5) 100
2,5-dimethyl-2,5-di (te
rt-Butylperoxy) hexane (0.2 parts by weight) was added, and the twin-screw extruder (ZSK-25; W was set to 250 ° C.).
Melt kneading was performed using ERNER & PFLEIDERER, Germany) to obtain polypropylene having a main peak molecular weight of 115,000 and a molecular weight distribution of 2.7.

[0031]

[Reference Example 4] Isotactic polypropylene (main peak molecular weight 278,000, molecular weight distribution 8.5) 100
2,5-dimethyl-2,5-di (te
rt-Butylperoxy) hexane (0.3 parts by weight) was added, and the twin-screw extruder (ZSK-25; W was set to 250 ° C.).
Melt kneading was performed using ERNER & PFLEIDERER, Germany) to obtain polypropylene having a main peak molecular weight of 100,000 and a molecular weight distribution of 2.6.

[0032]

[Reference Example 5] Isotactic polypropylene (main peak molecular weight 278,000, molecular weight distribution 8.5) 100
2,5-dimethyl-2,5-di (te
rt-Butylperoxy) hexane (0.05 parts by weight) was added, and the twin-screw extruder (ZSK-25;
Werner & Pfleiderer, Germany)
Melt kneading using a main peak molecular weight of 180,000,
A polypropylene having a molecular weight distribution of 4.1 was obtained.

[0033]

[Reference Example 6] Isotactic polypropylene (main peak molecular weight 190000, molecular weight distribution 5.4)

[0034]

Examples 1 to 5 and Comparative Examples 1 to 3 Polypropylene obtained in Reference Example, polyphenylene ether having reduced viscosity of 0.44, hydrogenated product of styrene-butadiene block copolymer (HTR-1; amount of bound styrene 65 wt. %, Polybutadiene portion hydrogenation rate 99.9%, number average molecular weight 830
00), hydrogenated product of styrene-butadiene block copolymer (HTR-2; bound styrene content 40% by weight, hydrogenation rate of polybutadiene part 99.9%, number average molecular weight 1).
(03000) was blended in a formulation shown in Table 1 using a Henschel mixer, and a co-rotating twin-screw extruder (ZSK2
5; Werner & Pfleiderer, Germany) was used and melt-kneaded at a preset temperature of 260 ° C to obtain extruded strands as pellets. The pellets obtained here were fed to a screw in-line type injection molding machine set at 250 to 280 ° C., and a test piece was injection-molded at a mold temperature of 55 ° C. using a tensile strength test piece mold having a weld portion. Using this test piece, a tensile strength test (according to ASTM D-638) was performed to measure elongation. The results are also shown in Table 1.

From these results, it was found that the composition of the present invention using the polyolefin having the specific molecular weight and the specific molecular weight distribution markedly improves the elongation of the weld portion.

[0036]

[Table 1]

[0037]

The polyolefin resin composition of the present invention is
Use of a polyolefin resin having a specific controlled molecular weight and molecular weight distribution improves the weld elongation of a molded article having a weld portion of a composition of polyolefin, polyphenylene ether and a compatibilizer, which has been difficult in the prior art. be able to.

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Claims (4)

[Claims] 1. The polyolefin resin composition has (a) a molecular weight of the main peak measured by GPC (gel permeation chromatography) of 200,000 or less and a molecular weight distribution (ratio of weight average molecular weight to number average molecular weight) of 3. Polyolefin-based resin of 0.5 or less 20
-60% by weight (b) Polyphenylene ether 30-60% by weight (c) At least one selected from hydrogenated aromatic vinyl compound-conjugated diene compound copolymer and hydrogenated vinyl aromatic compound-conjugated diene compound copolymer Copolymer of
A polyolefin resin composition comprising 5 to 35% by weight. 2. The polyolefin resin composition according to claim 1, wherein the polyolefin resin is a polypropylene resin which is an organic peroxide and has a main peak molecular weight of 200,000 or less and a molecular weight distribution of 3.5 or less. 3. The polyolefin resin composition according to claim 1, wherein the vinyl aromatic compound-conjugated diene compound copolymer is a vinyl aromatic compound-conjugated diene compound block copolymer. 4. The hydrogenated product of a vinyl aromatic compound-conjugated diene compound copolymer is a hydrogenated product of a vinyl aromatic compound-conjugated diene compound block copolymer.
The polyolefin resin composition according to 2 above.